There are various kinds of components (e.g., a light-emitting element, a liquid crystal element, and other various electronic components) for use in display devices such as an electroluminescence (EL) display, a plasma display panel (PDP), a light-emitting diode (LED) display device, and a liquid crystal display (LCD), and each of such the components has a temperature range in which the component can operate normally. If the temperature of the component exceeds a predetermined value or drops below a predetermined value due to an effect of an outside temperature, an ambient temperature of the component, and/or heat generated by the component itself, the display device might not operate normally; for example, the display device cannot maintain a favorable display condition, or has a trouble in its internal structure.
In order to deal with such the problems, there have been conventional techniques for adjusting a luminance level of a display device according to outside and/or internal temperatures of the display device (Literatures 1 through 4).
As one example of such the techniques, there is a technique for adjusting a luminance level of a display device for the purpose of (i) preventing a case (hereinafter, referred to as “temperature abnormality”) where a temperature of the display device becomes out of a temperature range in which the display device can operate normally or (ii) causing, if a temperature abnormality occurs, the temperature of the display device to be within the appropriate temperature range.
Typically, the higher the luminance level of a display device becomes, the more electric power the display device consumes. Consequently, the display device generates a larger amount of heat. In order to deal with this, for example, each of the techniques described in Literatures 1 through 3 causes, for the purpose of lowering an internal temperature of a display device, a control section (or a display driving section) for adjusting a luminance level of a light-emitting element to reduce the luminance level of the light-emitting element so as to suppress an increase in an amount of heat generation.
Meanwhile, Literature 4 focuses on temperature properties of liquid crystal. Specifically, Literature 4 discloses a technique for adjusting, according to an ambient temperature of a liquid crystal element (particularly, an outside air temperature), a luminance value which is to be supplied to a control section. This prevents display quality from being changed due to the outside air temperature, thereby maintaining a favorable display condition of an LCD independently of the environment of the LCD.